DEVELOPMENT OF A GIS-BASED SYSTEM FOR ANALYZING UNDERGROUND UTILIZATION

如今，城市地下被视为提供地铁网络等基础设施的新空间。在规划此类网络的路线时，必须考虑以下几个因素：土地使用模式和规划目标、土壤类型、现有交通网络、可能的环境影响等。此外，尽管大多数地下隧道都是在公共空间下建造的，但必须获得一些私人空间。因此，在评估不同的可能路线时，也必须考虑地役权成本。分析所有这些因素的相互作用及其对总建筑成本的影响的传统技术是繁琐、不准确和耗时的。在这项研究中，一个基于GIS的系统的开发，以调查实施GIS到这一领域的优点。该系统配备了几个空间数据库，其中载有研究区域的相关信息。一个分析系统，在用户定义的子程序的形式也包括处理所需的空间分析和成本评估。用户可以与系统交互以在水平和垂直方向上固定替代路线。在整个路线选择过程中，系统检查预定义的一组约束。然后从技术和经济角度对每条路线进行评估，并推荐最佳路线。使用开发的系统进行案例研究，比较几个路线和补偿方案。在本研究中，一个既有地铁线路的路线重新规划使用该系统和分析结果进行比较。在一般情况下，地理信息系统的实施到这一领域被证明是有前途的，可以大大提高地下基础设施的规划过程。

Nowadays, the underground of urban areas is regarded as an new space for infrastructure supply such as the provision of subway networks. In planning the route of such networks, Several factors have to be considered : land use patterns and planning objectives, soil types, existing transport networks, possible environmental impacts, etc. Moreover, although most underground tunnels are constructed under public space, some private space has to be acquired. Thus, easement cost must be also considered while evaluating different possible routes. Conventional techniques for an analyzing the interaction of all these factors and their effects on total construction cost is tedious, inaccurate, and time consuming. In this study, a GIS-based system is developed to investigate the merits of implementing GIS into this area. The system is equipped with several spatial data bases containing relevant information on a study area. An analysis system in the form of user defined subroutines is also included to handle required spatial analysis and cost evaluation. The user can interact with the system to fix alternative routes both in the horizontal and vertical directions. A pre-defined set of constraints are checked by the system throughout the route selection process. Each route is then evaluated from technical and economical viewpoints and best routes are recommended. A case study is carried out using the developed system to compare several alignments and compensation schemes. In this study, the route of an existing subway line is re-planned using this system and analysis results are then compared. In general, the implementation of GIS into this area proved to be promising and can greatly enhance the planning process for underground infrastructure.